A display subsystem for an electronic device such as a mobile device may consume a significant amount of power due to the large amount of data transfer between the image data generator, such as an application processor, to a display device, such as and LCD (Liquid Crystal Display) panel, via a display frame buffer that temporarily stores image data. For this reason, minimizing the power consumption of the data transfer is a key factor in the design of a low power mobile device.
For example, techniques exist for reduction in the amount of data transfer. Display Selective (or Partial) Update (DSU) reduces the amount data transfer by transferring only a partial frame that includes data that differs from the previous frame, with a display frame buffer being inserted to retain the data for a full frame. In this manner, the amount of data that is transferred between the image generator and the display device is reduced, which leads to a reduction in the overall power consumption for the display transfer.
However, techniques to reduce the amount of data transferred does not directly address the power that is consumed by the display frame buffer in display operation, which is a significant power cost in the operation of a mobile device that has a limited power source. The increasing resolution of displays in mobile devices requires additional data, and thus additional power is required for the reading and writing of such data in the display frame buffer.